Work piece sensor and tape cutoff for sewing machines

ABSTRACT

The present machine is for affixing binding tapes to articles and including attachments for such machines which allow the machine to be run either manually or automatically. In the automatic position of the attachments, they start the machine, upon presentation of a work piece to the machine, cut the tape at the start and finish of the work and stop the machine automatically. Also the operator can run the machine manually and stop the machine at any time when running the machine in said automatic position of the attachments.

ilnite States Patent [1 1 Miller et a1.

[ WORK PIECE SENSOR AND TAPE CUTOFF FOR SEWING MACHINES [76] Inventors:Roy E. Miller, 1301 Stuart Dr.,

Mechanicsburg, Pa. 17055; Robert F. Miller, 128 W. Clearview Dr., CampHill, Pa. 17011 [22] Filed: Oct. 22, 1968 [21] Appl. No.: 769,512

Related [1.8. Application Data [60] Division of Ser. No. 695,812, Oct.31, 1967, Pat. No. 3,425,373, which is a continuation-in-part of Ser.No. 504,396, Oct. 24, 1965, abandoned.

[52] 11.8. CI. 112/219 B [51] Int. Cl. D05b 69/22 [58] Field of Search112/220, 219 R, 219 A,

[56] References Cited UNITED STATES PATENTS 1,839,495 1/1932 Paynter192/128 X 111 3,754,522 [451 Aug. as, 1973 3,133,481 5/1964 McCormick eta] 192/128 X 3,156,204 11/1964 Hamich et a1. 112/219 X PrimaryExaminer-H. Hampton Hunter Attorney-William C. Linton et a1.

The present machine is for affixing binding tapes to articles andincluding attachments for such machines which allow the machine to berun either manually or automatically. in the automatic position of theattachments, they start the machine, upon presentation of a work pieceto the machine, cut the tape at the start and finish of the work andstop the machine automatically. Also the operator can run the machinemanually and stop the machine at any time when running the machine insaid automatic position of the attachments.

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R BE T E g- 010 ROY E.MI|.LER BY jun-W 51:

WORK PIECE SENSOR AND TAPE CUTOFF FOR SEWING MACHINES DESCRIPTION Thepresent application is a division from my copending application Ser. No.695,812, filed Oct. 31, 1967, now US. Pat. No. 3,425,373 dated Feb. 4,1969, which in turn is a continuation-in-part application of applicationSer. No. 504,396 filed Oct. 24, 1965 and now abandoned.

The present invention is directed to an improvement in tape applyingmachines and is more particularly concerned with machines for applyingbinding tape to articles.

It is the principal object of the present invention to provide aconventional sewing machine or adhesive tape applying machine withattachments which permit the machine to affix a binding tape onarticles, for example, canvas or leather shoe uppers, and which machinecan be either manually or automatically operated and when automaticallyoperated presentation of the article and binding to the machine willautomatically start the machine, the binding tape will autmatically becut at the start and finish of the work, and the machine will be stoppedafter the cutting of the binding tape and before a second work piece ispresented to the ma chine.

A further and important object of theinvention is to provide attachmentsfor conventional sewing machines for attaching binding tape to a workpiece and which attachments sense the movement of the binding and workpiece during the sewing operation for automatically starting and runningthe sewing machine, cutting the binding close to the leading edge of thework piece, cutting the binding a second time close to the finish of thework piece and stopping the operation of the sewing machine thereafterand yet which attachments permit the sewing machine to be manuallyoperated for the starting and stopping thereof without the bindingcutting steps. g

A still further object of the invention is to provide an attachment forconventional types of sewing machines for applying binding to articlesand which attachment can be used to automatically start and stop thesewing machine before and after the sewing of each article and severingthe binding at the leading and trailing edges of the work piece betweenthe starting and stopping of the sewing machine and which attachmentfurther is long lasting, requiring little or no maintainance and reducesthe ability required of the operator for such sewing machines whilepermitting an increase in production at less cost of the articles beingsewn.

Further objects of the invention will be in part obvious and in partpointed out in the following description of the accompanying drawings inwhich:

FIG. 1 is a perspective view of a sewing machine incorporating thepresent attachment.

FIG. 2 is an enlarged perspective view of the binding, sewing andcutting portion of the sewing machine as viewed from FIG. 1.

FIG. 3 is a further perspective view of the binding, sewing, and cuttingportion of the sewing machine as viewed from the opposite side of FIG.2.

FIG. 4 is a front elevation of the present sensing attachments for thesewing machine.

FIG. 5 is a top foreshortened view of the sensing and cuttingattachment.

FIG. 6 is a side elevation partly in section of the sensing and cuttingattachment.

FIG. 7 is a perspective view of a portion of the knife follower saddleforming a part of the sensing attachment.

FIG. 8 is an enlarged exploded detailed perspective view of the elementsof the sensing and cutting attachment.

FIGS. 9a and 9b are diagrammatic showings of the pneumatic andelectrical circuit for the present invention.

FIG. 10 is a perspective view of a sensor forming part of the presentpneumatic circuit.

FIG. 11 is a top view of said sensor with interior details shown indotted lines.

FIG. 12 is a cross sectional view taken on line 12-12 of FIG. 10.

FIG. 13 is a cross sectional view taken on lines 13-13 of FIG. 12.

FIG14 is a cross sectional view taken of an electrically operatedsolenoid valve forming part of the present attachment.

FIG. 15 is a top view of a modified form of cutting and sensingattachment.

FIG. 16 is a side elevation partly in section of FIG. 15.

FIG. 17 is an end view of the top sensor element.

FIG. 18 is an end view of the bottom sensor element.

FIG. 19 is an enlarged exploded view of said modified form of cuttingand sensing attachment.

FIG. 20 is an enlarged perspective view of the modified cutting andsensing attachment taken from the top of FIG. 15.

FIG. 21 is a partial end perspective view of FIG. 20 with the sensingelements removed.

FIG. 22 is a further enlarged top view of the sensor end portion of FIG.20 with the top sensor elements removed.

FIG. 23 is a bottom perspective view of the cutting element of FIG. 20.

And FIG. 24 is an enlarged front view, partly broken away, of the kneeswitch.

FIG. 25 is an enlarged cross-sectional view taken on line 25-25 of FIG.24.

Referring now more particularly to the accompanying drawings whichinclude a conventional sewing machine by way of an example only for usewith the present invention and wherein like and corresponding parts aredesignated by similar reference characters, numerals l and 2 indicate apair of standards connected by a tie bar 3 upon which is pivotallysupported a foot pedal 4 having an operating rod 5 pivotally connectedthereto at 6. A table top 7 is supported by said standards and supportsa box 7a containing relays, sensor operated micro-switches andindicators for the present attachment described more in detailhereinafter. A base 8 of a conventional sewing machine 9 is fixedlymounted on said table top, a box 7b is mounted beneath said table topand has an electrical lead-in cable 7c from box 7a and feed cable 7d andcontains an off-on switch 7e and a manual-automatic switch 7f. Sewingmachine 9 can be, for example, a model 47W sewing machine as produced bythe Singer Company for use with the sensing and cut off attachmentsshown in FIGS. 18 inclusive or a model 108 sewing machine for use withthe sensing and cut off attachments as shown in FIGS. 15 to 23.

However, it is to be appreciated that the invention can be used withother types of sewing machines.

A knee-switch 7g as shown in FIGS. 1 and 24 is attached to the bottom oftable top 7 by screw 305 extending through plate 304. An arm 306 isattached to plate 304 as by welding and a clamp 307 consisting of twosplit rings fixedly joined together has arm 306 extending through one ofsaid split rings and a rod 308 extending through the other split ringwith screws 3070 for tightening or loosening said split rings. A collar309 has rod 308 extending therethrough and a set screw 310 extendingthrough and in threaded engagement with collar 309 for positioning saidcollar on rod 308. A coil spring 311 has rod 308 extending therethroughand one end bent around set screw 310. A knee-plate 312 has tubularportions 313 and 313a through which extends rod 308 pivotally supportingsaid knee-plate. An end 31 1a of spring 311 extends alongside saidkneeplate while said knee-plate has a stop 315 normally engaging screw317 extending through and in threaded engagement with collar 316retaining collar 316 on rod 308. A micro-switch 318 is attached to rod308 by screws 319 and has a plunger 314 to be operated at times by saidknee-plate.

Said sewing machines have the conventional hand wheel 10 to which isattached an endless belt 11, a thread spool 12a and thread guide 12 anda sewing head 13 and base arm 14. Said head carries the conventionalneedle reciprocating arm 13a with needle 13b alongside pressor foot 13cabove the feed dog 13d of the base arm 14. Operating rod 5 is connectedto pressor foot 130 by conventional means (not shown) for raising andlowering said pressor foot. Said base arm also has pins 15 mountedthereon for guiding the binding tape 16 from a supply thereof, notshown, towards said pressor foot.

A combination brake and clutch unit 17 is fixedly supported beneathtable top 7 and has an electric motor connected by wire 18 to a sourceof electrical current. Said brake and clutch unit is of the same type asshown in applicants copending application Ser. No. 459,638, filed May28, 1965, now US Pat. No.

3,359,931 Dec. 26, 1967, and which clutch and brake unit has a drivenpulley 17a around which extends endless belt 11 for starting, runningand stopping said sewing machine.

Pipe 19 is connected to a source of air under pressure (not shown) andhas a filter unit 20 and pressure regulator 21 interconnected thereinand is connected by tube 24 to a port of a solenoid exhaust valve 22. Asecond port of said solenoid exhaust valve is connected to an oiler unit23 by tube 155 and said oiler unit is connected by tube 156 to a port ofsolenoid brake valve 25, and to a port of solenoid drive valve 27.

The sensing and cut off unit of the present attachment has a plate 28which is fixedly attached to the sewing head 13 of the sewing machine 9as best shown in FIG. 1 and which plate has a lateral finger 29 which aslot 30 therein. Three tubes 31, 33, and 35 have nuts 32, 34 and 36respectively fixedly attached to their ends while screws 37 extendthrough slot 30 to said nuts adjustably retaining said tube endsadjacent the bottom edge of said finger.

Plate 28 also has an opening 38 through which screw 39 extends intoopening 550 in attaching block 55 in threaded engagement therewith.

Plate 28 further has opening 40 with clamp 41 being attached to saidplate by a screw 43 extending through opening 42 in said clamp andopening 40 retained by washer 44 and nut 45.

A cylinder block 46 has opening 47 through which extends screw 49through washer 48 into an opening (not shown) in flange 50 of attachingblock 55 in threaded engagement therewith. Said cylinder block furtherhas an opening 51 with screw 53 extending through washer 52, opening 51and opening 54 of attaching block 55 in threaded engagement therewith.

Said attaching block has an opening 55a in which is positioned asemi-circular sleeve 56 retained by screw 55b, providing a bearing forthe sliding therethrough of a conventional pressor foot control element(not shown).

Said cylinder block also has a back recess 57 in which is positionedguide bar 60 against springs 58 and 59 while screws 63 and 64 passthrough openings 61 and 62 in said guide bar and said springs intothreaded openings in said cylinder block, see FIG. 6.

Said cylinder block 46 further has a bore 65 through which extends apiston rod 66. Piston rod 66 has a side recess 66 in which said guidebar is positioned and which provides cam 66b and apiston 67 upon the topof which is positioned a ring 68 with said piston and ring slidablymounted within the bore of cylinder 69 which is in threaded engagementwith cylinder block 46 around bore 65. Cylinder 69 has a threadedopening 70 in which is positioned threaded end 72 of elbow 71 while athreaded nipple 73 is also in threaded engagement with said elbow.

Said piston rod further has a recessed end 74 with opening 75therethrough while a knife blade 76 is positioned in said recess and aplate 77 is held against said knife blade by a screw 78 extendingthrough opening 75 in threaded engagement therewith. Pins 76a extendthrough opening 76b in said piston rod, opening 76c in said knife bladeand openings 76d in plate 77.

A bushing 79 is positioned on said piston rod below piston 67 while aspring 80 is mounted in bore 65 and pushes against said bushing 79tending to move said piston rod upwardly drawing said knife blade 76towards cylinder block 46.

A micro-switch base 81 has a side opening 82 for receiving screw 83 anda second opening 84 for receiving a screw 85 which screws extend intosupport 86 and micro-switch 87 for supporting the same in said base. Aplunger 87a is slidably mounted in cylinder block 46, see FIG. 6, forbeing pushed by cam 66a of said piston rod when said piston rod reachesthe end of its stroke to activate micro-switch 87. A cover 88 for base81 has recesses 89 and 91 for receiving screws and 92 which extend intoopenings 90a and 92a in said base 81 detachably retaining the coverthereon. Screws 94 extend through washers 93 and openings 94a in saidmicro-switch base and into cylinder 46 as shown in FIG. 3 for attachingsaid micro-switch to said cylinder block.

A cylinder cover 95 extends around the lower portion of the sewingmachine base arm 14 as shown in FIGS. 2 and 3 with a bedcap 96 againstdisc 97 of said sewing machine base arm.

A throat plate 98 is mounted upon said bedcap. Said disc 97 has opening99 while bedcap 96 has an opening 100 for receiving a screw 101 inthreaded engagement therewith. Likewise bedcap 96 has opening 104 anddisc 97 opening 105 for receiving screw 106 in threaded engagementtherewith retaining the sametogether. Openings 107 and 109 are providedin a sensor holding plate 112 for receiving screws 108 and 110respectively while said sensor plate is inserted in opening 111 in saidbedcap with screws 108 and 110 being in threaded engagement withopenings 108a and 110a respectively of disc 97. Tubes 113, 115 and 117have nuts 114, 116 and 118 respectively fixedly connected thereto whilescrews 1l9 extend through slot 120 in sensor holding plate 112 each inthreaded engagement with one of said nuts for adjustably supporting saidtubes with their open ends below throat plate 98.

Said bedcap has a side recess 121 in which is positioned a knife cuttingbar block 122 with screws 124 extending through openings 123 and screw126 extending through opening of said knife bar block into said bedcapretaining the supported flange 127 on top face 128 of said bedcap andabove said throat plate 98. Bedcap 96 further has a top face 129 uponwhich is seated finger guard 130. A screw 131 extends through openings132 in said finger plate into openings 1320 of disc 97. Side 133 of saidthroat plate 98 extends below face 128 of said bedcap while side 1330 ismounted upon end 12% of said bedcap and has top openings 134 for theconventional feed dog of the .sewing machine.

Plate 135 is attached to base arm 14 by screw 135a for retaining oneside of cylinder cover 95 thereon.

A tape guide 136 is mounted upon the top of said cylinder arm andretained by screws 137 for twisting the binding tape 16 to a flatposition beneath the pressor foot 13c. A second plate 138 is alsomounted on said cylinder arm by screw 139 and thumb screw 140 forretaining the other end of said cylinder covering the said arm.

A nipple 73 is threadedly attached to elbow 71 and connected to tube 141connected to air valve cutting solenoid 142, which has exhaust port1420. A second nipple 143 is also connected to a second port of saidsolenoid cutting valve 142 and to a tube 144.

Wires 145 and 145a are connected to said solenoid cutting valve whilewires 146 are connected to microswitch 87.

Tube 147 is connected to tube 144 and one port of a start-stopmicro-switch sensor block 174 while tubes 35 and 117 are attached toother ports of said microswitch sensor block.

A tube 149 is also connected to tube 144 and one port of a second cutmicro-switch sensor block 150 while tubes 31 and 113 are attached toother ports of said second cut micro-switch sensor block.

A tube 151 is also connected to tube 144 to one port of a first cutmicro-switch sensor block 152 while tubes 33 and 115 are connected toother ports of said microswitch sensor block 152.

Said micro-switch sensor blocks 174, 150 and 152 are more fullydisclosed in FIGS. 10-13 inclusive and will be described more in detailhereinafier.

A solenoid shut ofi valve 153 has tube 154 connected to one port thereofand also to tube 155 and a second port connected to tube 144. A tube 156connects the lubricating cylinder 23 to one port of drive solenoid valve27 and by a tube 157 to a port of brake solenoid valve 25. A second portof said brake solenoid valve 25 is connected by tube 159 to the brakeoperating port of the clutch and brake unit 17. A tube 161 connects aport of the drive solenoid valve 27 to the drive port of said brake andclutch unit 17 and includes a flow control 160. A tube 162 connects theexhaust port of said drive solenoid valve 27 to the exhaust port ofexhaust solenoid valve 22 and by tube 163 to a further port of the brakesolenoid valve 25. Tube 164 connects tube 162 with the exhaust port ofsaid brake and clutch unit 17.

Wire 165 is connected to the solenoid of shut-off solenoid valve 153 asis a wire 166 which is also connected to wire 145. Wire 167 is connectedto the exhaust solenoid valve 22 as is wire 168 which is also connectedto wire 169 to brake solenoid valve 25 and to the drive solenoid valve27. A wire 170 is connected to both said brake and drive solenoid valves25 and 27 and to a wire 171. Also wire 172 is connected to wire 168.

The electrical connection posts for the drive motor of the clutch andbrake unit 17 are indicated at 173.

The micro-switch 87 of FIG. 9a is tied into FIG. 9b by dotted lines A,while sensor blocks 152, 150 and 174 of FIG. 9a are tied into theirmicro-switches of the same number in FIG. 9b by lines B, C, and Drespectively. Likewise wires 167, 171, 172, 145, 145a, and 165 of FIG.9a continue on FIG. 9b as E, F, G, H, I, and J, respectively.

The micro-switch sensor blocks 174, 150 and 152 are similar andtherefore, micro-switch sensor block 174 is shown in FIGS. 10-13 asrepresentative of all three. Said micro-switch sensor block 174 has abushing 175 extending therein and which bushing has adjusting stem 176in threaded engagement therewith and extending therethrough into an aircontrol seating disc 177 having a tapered opening providing a needlevalve. Said disc is held within said sensor block by a cap 178 inthreaded engagement with said block. A passageway 179 leads to one sideof said seating disc 177 and to threaded ports 174a and 174b. A threadedport 1740 extends into said sensor block and connects with a passageway180 adjacent said adjusting stem and also in communication with alateral passageway 181 leading to recess 182 in said block. A diaphragm183 extends across recess 182 and is held thereon by micro-switch 148while a plunger 184 is mounted on said diaphragm and positioned foroperating said micro-switch.

Tube 35 is connected to port 1740 while tube 147 is connected to port174b and tube 117 is connected to port 174c by being in threadedengagement therewith.

The amount of air to pass from passageway 179 to 180 is controlled byadjusting stem 176 relative to disc 177.

When the pressure within passageway 181 is relatively high as when awork piece is between the ends of tubes 35 and 117 stopping the flow ofair therefrom diaphragm 183 is moved upwardly operating microswitch 174.However, when the pressure below diaphragm 183 is lowered as when saidwork piece passes from between the ends of tube 35 and 117 the diaphragmis lowered again operating micro-switch 148.

The exhaust solenoid 22 is a conventional three-way solenoid valve suchas are solenoid valves 142, 25 and 27 as produced by the AutomaticSwitch Company. An enlarged view of solenoid valve 22 is shown in crosssection in FIG. 14 as an example of all three solenoid valves. Saidvalve has base 185 with a passageway 186 to which is connected tube 24and a center passageway 187 connected to tube 155. A plunger 188 isslidably mounted in the bore of tube 189 surrounded by an electricallyoperated solenoid 190 connected to wires 167, and 168 and said plungernormally closes passageway 187. The bore of tube 189 further isconnected to tube 162. Thus when air enters from tube 24 into passageway186 and the solenoid is deenerg'ized said air passes around plunger 188through tubes 189 and 162 to the exhaust port of the clutch and brakeunit 17. However, when solenoid 190 is energized it raises plunger 188permitting the air to pass from passageway 186 to passageway 187 to tube155.

Solenoid valve 153 is a conventional two-way solenoid valve which can beobtained from the Automatic Switch Company and is similar to solenoidvalve 22 except that it does not have the exhaust opening but a plungersuch as 188 merely opens and closes two pas sageways similar topassageways 186 and 187 to permit the connecting and disconnecting oftubes 144 and 154 by solenoid valve 153.

In the operation of the sewing machine with the present attachmentsconnected thereto air under pressure is fed into tube 19 whileelectrical current is supplied to posts 173 for driving the clutch andbrake unit and also to cable 7d. With the switch 7f in its manualposition, that is connected to point 7i and switch 7e closed, current issent through line B to the exhaust solenoid 22 supplying air to tube 155to tube 154 and to tube 156 and by tube 157 to solenoid brake valve 25and also to solenoid drive valve 27. At the same time current issupplied to switch 7g, but will proceed no further due to switch 7gbeing in its normally open position as shown in FIG. 9b. When theoperator moves the knee lever controlling switch 7g, said switch will beclosed directing current through line F to the brake and drive solenoidvalves 25 and 27 operating the same driving the sewing machine allowingthe operator to perform a sewing operation without the automaticcontrols. That is the cut off unit 69 will not cut the binding 16 sinceshut ofi' valve 153 is in its closed position. Whenever the knee leveris released by the operator switch 7g will open stopping the sewingmachine. Thus when solenoid valve 25 is deenergized air will pass fromtube 157 to tube 159 to the brake port of the clutch and brake unit 17stopping pulley 17a and thus sewing ma chine 9. However, when saidsolenoid valve 25 is energized then tube 157 is closed and air from tube159 is exhausted through tubes 163 and 164 to the exhaust port of unit17 leaving pulley 17a free.

When solenoid valve 27 is energized air passes from tube 157therethrough to tube 161 and the drive port of unit 17 causing therotation of pulley 17a running the sewing machine 9. However, when saidsolenoid valve 27 is deenergized air from tube 161 is exhausted throughtube 162.

With switch 7 in its automatic position, that is connected to point 7hand switch 7e closed, current is sent through line B to the exhaustsolenoid 22 and through line .I to the shut-off solenoid 153 controllingthe air feed to the cutter 67 and sensors Nos. 1, 2 and 3. At the sametime current will be supplied to the common lead K to the micro-switch87, and the micro-switches of sensor blocks 152, 150 and 174 and thuslines B, C, D, as said micro-switches 148 of sensor blocks will beclosed as shown in FIG. 9b, when work is presented to the sewingmachine. When there is no work in the sewing machine said common leadwill be connected to the lower contacts of the micro-switches 152, 150and 174. The current from said common lead to micro-switch 8'7 will feedthrough micro-switch 87 back to the lefthand switch on relay 191. Asrelay 191 is not energized at this point the lefthand switch thereofwill be open preventing the current from proceeding further in thecircuit. The current passing through micro-switch 152, when there is nowork in the sewing machine, will pass from the common lead K through thelower contact of micro-switch 152 to energize light 195. At the sametime the current is passing to the right hand switch of relay 194, butsince the switch is open the current will proceed no further. Thecurrent from common lead K to micro-switch 1511 will pass through thelower contact thereof to energize light 196' and at the same time goesto the left hand switch of relay 193 which is open preventing thecurrent from proceeding further. The current from switch 174 passesthrough the lower contact thereof to energize lamp 197.

When a work piece such as a canvas or leather shoe upper is passedbetween tubes 35 and 117 an increase in pressure occurs in themicro-switch sensor block 174 closing said microswitch as shown in FIG.9b at which time the current is supplied from the common lead K onmicro-switch 148 of sensor block 174 through switch 7g which is in itsclosed position also as shown in FIG. 9b and goes from there to thebrake and drive solenoids 2S and 27 driving the sewing machine. As longas the work piece remains in the sewing machine micro-switch 148 ofsensor block 174 will remain closed and the sewing machine will continueto sew. Sensor block 174 includes a micro-switch 148 as does sensorblocks 150 and 152.

As the work piece is moved to between tubes 33 and 115 the pressure inthe microswitch sensor block 152 increases and said micro-switch 148 ofsensor block 152 will move to the position shown in FlG. 9b at whichtime current will be fed from the common lead K through saidmicro-switch of sensor block 152 to the normally closed contact of themiddle switch of relay 191 and through this middle switch to the cuttingsolenoid 142 which opens and admits air to the top of cylinder movingthe cutting knife 76 down to cut the binding 16. As the piston rod 66approaches the end of its downward stroke cam 66d pushes plunger 87aagainst micro-switch 87 moving the same so that the common lead K willbe joined to the lower contact of micro-swtich 87 sending current to theleft hand switch of relay 192 and therethrough to the coil of relay 191energizing said coil. As the coil to relay 191 is energized it will movethe three switches of relay 191 to the right and at this point the powerconnection through the middle switch of relay 191 to the cuttingsolenoid 142 will be broken de-energizing said cutting solenoid 142releasing the air above piston 67 through exhaust port 1420 of thecutting solenoid 142 so that spring 80 returns the cutter 76 to itsupper position. At the same time a holding circuit will be formedthrough the right hand switch of relay 191, to hold the coil of relay191 energized. As the cutter 76 returns to its upper position themicro-switch 87 will once again move to the position shown in FIG. 9bthereby sending current from the common lead K through the upper portionof microswitch 87 through the left hand switch of relay 191 to the coilof relay 192 energizing the coil thereof, moving the switches of relay192 to the right forming the holding circuit for the coil of relay 192keeping it energized and holding its switches in their right handposition.

As the work piece is moved between tubes 31 and 113 air pressureincreases in the micro-switch sensor block 150 moving the micro-switchthereof to its position shown in FIG. 9b and when the micro-switchcloses as shown, current will be sent from the common lead K to the coilof relay 193 moving the switches of relay 193 to the right and forming aholding circuit retaining the coil of relay 193 in an energizedcondition and the switches thereof in their right hand position.Therelays and their switches will remain in these positions during thesewing operation on the work piece. Relay 191 thus cancels the currentto the cutting solenoid 142 so that knife 76 does not make a second cutof the binding 16 until the work piece leaves the tube 31 and 113.

As the work piece is further moved clearing the sensing tubes 31 and113, micro-switch 148 of sensor block 174 will move to its lowerposition stopping the sewing machine. The micro-switch of sensor block152 will also move to its lower position at which time current will besupplied to the right hand switch of relay 194 but will proceed nofurther due to the fact that relay 194 is-in its de-energized position.Light 195 will also be lighted. When the work piece clears the sensortubes 31 and 1l3 the micro-switch of sensor block 150 will move toitslower position energizing lamp 196, but current will be fed throughthe left hand switch of relay 193 which is in its right hand positionand the current thus will pass through the middle switch of relay 194back through the middle switch of relay 192 which is in its right handposition,.andvback through the middle switch of relay 191 which is inits right hand position, to cutting solenoid 142. The cutter blade 76will then be caused to descend until it reaches the bottom of its strokecutting binding 16 close to the finish of the work piece and movingmicro-switch 87 so that the common lead K is connected to the lowercontact of microswitch 87 feeding current through the left hand switchof relay 192 which is in its right hand position, and to the coil ofrelay 194 energizing the same, moving its switches to the right. Whenthis occurs the current being fed to the cutting solenoid 142 will bebroken by the middle switch of relay 194 permitting outer blade 76 toreturn to its upper position. At the same time the return circuit forthe coils of relays 191, 192 and 193 which goes through the left handswitch of relay 194 will be broken thereby de-energizing each of theserelays allowing their switches to move to their left hand positions.Simultaneously with the return of the cutter blade 76 to its upperposition, micro-switch 87 again moves to its position as shown in FIG.9b and the current from the common lead K goes to the open left handswitch of relay 191.

When relay 194 was energized, a holding circuit was formed through themicro-switch of sensor block 152 and the right hand switch of relay 194to maintain the relay 194 in its energized position and with itsswitches to their right hand position. Relay 194 remains energizedbetween the introduction of work pieces to the sewing machine. When afurther work piece is fed to In the aforementioned description of theoperation of the present apparatus reference to right, left, up or downfor the elements refers to these directions on FIG. 9b.

Lamps 195', 196, 197' and 198 are connected to cable 7d and lamp 195' isconnected to the microswitch of sensor block 152, lamp 196' to themicroswitch of sensor block 150, lamp 197 to the microswitch of sensorblock 174 and lamp 198' to switch 7e. Thus, lights 195', 196' and 197'are only lit as long as there is no work piece in the sewing machine andthey will be turned off as soon as the micro-switches of sensor blocks152, and 174 are actuated. Further light 198' is always lit as long asthe current is turned on to the sewing machine whether switch 7f if inthe manual or automatic position.

FIGS. 15-23 inclusive disclose a modified form of sensor and tapecut-off unit particularly for use with a model 108 sewing machine asproduced by the Singer Company. Certain elements of this modified deviceare similar to those used in the device shown in FIG. 8 and have beengiven corresponding reference numerals.

Block is a conventional part of said sewing ma chine and a plate 196 ismounted on the top thereof having openings 197 in which are positionedtubular washers 198 above which aremounted rings 198a. A block 199 ismounted upon plate 196 and has openings 200 which match with openings197 for receiving screws 201 therethrough into threaded engagement withblock 195. Block 199 also has a recess 202 in one end and an invertedT-shaped groove 203 extending from the top thereof.

A plate 204 has a tongue 205 extending into recess 202 and having anopening 209 coinciding with opening 206 in plate 196 while a spring 207extends into opening 209 and screw 208 extends through said spring andopenings 209 and 206 into threaded engagement with block 195.

Bolt 210 has its head slidably positioned in recess 203 and extendsthrough opening 21 1, washer 212 and has nut 213 thereon retaining arm214 on block 199 with said'arm extending laterally therefrom. Said armfurther has a curved support 215 extending laterally of the same with aflat end 216 through which extends slots 217 for receiving screws 218therethrough to engage openings 301 in cylinder block 279 for retainingsaid cylinder block on the right hand side of support 215. An L-shapedplate 219 is fastened to end 216 of support 215 by screws 222 whichextend through washers 221, openings 220 in said L-shaped plate and intothreaded openings 223 in end 216. Support 215 has opening 224 againstwhich is positioned the washer 225 and through which extends screw 226into a threaded opening 303 in the cylinder block 279. L-shaped plate219 also has openings 227 which match with openings 2280 of a sensor arm228 with screws (not shown) passing through openings 228a into threadedengagement wtih openings 227. A spring 230 has an opening 229 for ascrew (not shown) in threaded engagement with opening 231 in said sensorarm whereby said spring extends across slot 234. Said sensor arm alsohas slot 232 through which extends screws 233 into threaded openings inblock 32, 34 and 36 fixedly connected to and supporting sensor tubes 31,33, and 35 respectively.

said openings 236 into threaded openings (not shown) in recess 235awhereby said bar extends beneath support 215. Said bar also has alateral groove 239 in the opposite end thereof together with a flat topface 240. A knife cutting bar 241 has key 242 seated in recess 239 and alongitudinal recess 243. A knife follower 244 is mounted upon face 240of bar 235 below recess 243 and has a slanting edge 245 extending intosaid recess 243. Knife cutting bar 241 also has a threaded opening 247in alignment with opening 246 in said arm 235 while a screw 249 extendsthrough washer 248 and opening 246 into threaded engagement with opening247.

Said knife follower 244 has an elongated opening 250 in alignment withthreaded opening 251 in said arm 235. A current spring 244a has aslotted opening 244b in alignment with the opening 251 on the bottom ofarm 235 and with its free end 244c adapted to lie 'on the surface 240 ofarm 235 against the edge of knife follower 244 opposite the edge 245. Ascrew 253 extends through washer 252 opening 244b, threaded opening 251and into slotted opening 250. Thus spring 244a will urge the knifefollower 244 into engagement with the far edge of recess 243 and theknife follower 244 will be free to move on the end of screw 253 againstthe action of spring 244a when the knife descends. A pressor foot 254 isshown for use with the present device and has an opening 255 forreceiving a screw for attachment to the conventional pressor footlifting rod (not shown) of the sewing machine.

A second sensor support 256 has an elongated slot 257 in which arepositioned the nuts 258 fixedly attached to the sensor tubes 113, 115,and 117 with said nuts retained in slot 257 by screws 259 in threadedengagement with openings 260 and against nuts 258 whereby tubes 113, 115and 117 can be adjustably aligned with tubes 31, 33, and 35respectively. Said sensor support 256 also has an opening 261 throughwhich extends a screw 262 into threaded opening 262a of bar 235. Athroat plate 263 has a recess 263a receiving the tongue 204a of plate204 and also an opening 264 having a screw extending into a conventionalthreaded opening (not shown) in the end of the arm 14 of the sewingmachine.

Support 215 has threaded openings 265 matched with openings 267 in aplate 266 with screws 268 extending through the openings 267 intothreaded engagement with openings 265. Plate 266 also has openings 269through which extends screw 270 into the threaded openings (not shown)in the bottom of the solenoid valve 271 in threaded engagementtherewith. Said solenoid valve also has a threaded opening 272 withnipple 273 therein and connected to a pipe coupling 273a connecting thesame to tube 144. A second nipple 274 is connected to the opposite sideof said solenoid valve and also to a pipe coupling 275 for being joinedto tube 141. A cover 276 is mounted upon the end of said solenoid valveand has exhaust opening 142:: for said solenoid opening therethrough.

Tube 141 is also fastened by coupling 277 to nipple 278 joined tocylinder 69 having piston ring 68 and piston 67 slidably mountedtherein. Said piston has ring 79, spring 80 and cutting blade 76 asdescribed in the form as shown in FIG. 8 with piston rod 66 extendinginto bore 280 in the cylinder block 279 while cylinder 69 is in threadedengagement with thread 281 of said cylinder block. Said cylinder blockhas openings 282,

a rear recess 283 with springs 284 and block 285 mounted in said recessagainst the recess 66a in piston rod 66 and retaining in position byscrews 287 extending through openings 286, springs 284 into threadedopenings 282. Plunger 87a is slidably mounted insaid piston block asbest shown in FIG. 16 for being moved by cam 66b of said piston rod.

A micro-switch supporting block 288 has a recess 289. A cover 290 forsaid micro-switch block has recesses 292 for receiving screws 291 whichextend into openings 298 of said block and retaining said cover thereon.Said block further has openings 293 into which extend screws 294 intothreaded openings (not shown) in the rear of said cylinder for retainingthe same together. Micro-switch 295 is positioned in block recess 289and has openings 296 and 297 while screws 299 extend through openings300 of block 288 and openings 296 and 297 of said micro-switch retainingthe same together. A spring 302 having a spring arm 303 in positionedbetween the contact of the microswitch and plunger 87a for activatingsaid micro-switch when said plunger is moved.

The operation of the sensor and cutting element of FIGS. 15-19 inclusiveis substantially the same as described for the modification shown inFIGS. 4 to 8 inelusive. That is the sensor tubes 31, 33 and 35 areadjustably positioned relative to tubes 113, 115 and 117 for sensing thepassages of the work piece therebetween and operating the present systemshown in FIGS. 9a and 9b so that when air is passed to tube 141 pistonrod 66 is lowered against spring and the knife blade 76 cooperates withthe knife cutting bar 241 and knife follower 244 severs the binding tape16 thereon and at the same time cam 66b operates plunger 87a and thusmicro-switch 295 in a similar manner to that previously described.Likewise solenoid valve 271 functions in the same manner as solenoidvalve 142.

Knee-switch 7g is normally open in that spring 31 l by its end 311atends to pivot knee plate 312 away from micro-switch plunger 314 andstop 315 against screw 317. However, the operator can by using a kneepush knee plate 312 against plunger 314 closing microswitch 318 whendesired.

Sensing tubes 31, 33 and 35 can be omitted without changing operation asthey mainly blow lint away.

The present invention is capable of considerable modification and suchchanges thereto as come within the scope of the appended claims aredeemed to be a part of the invention.

We claim:

1. In a sewing machine having a sewing head above a base arm, anattachment therefor for starting and stopping said sewing machinecomprising a clutch and brake drive unit operatively connected to saidsewing machine having an air operated brake section and an air operatedclutch section, a plurality of solenoid valves connected together withone of said solenoid valves connected to a source of air under pressure,a second of said solenoid valves connected to the brake section of saidclutch and brake unit, a third of said solenoid valves connected to saidclutch section of said clutch and brake unit, two pairs of tubes witheach pair thereof having facing, but spaced apart ends for the passageof a work piece to be sewn, said pairs of facing tube ends being spacedapart in the direction of movement of the work .piece, and air operatedmicroswitches each connected to one pair of said facing tubes and to oneof said first mentioned solenoid valves and electrical means operable bysaid micro-switches in sequence when the work piece passes between theends of the first pair of facing tube ends for operating the operatingthe second of said solenoid valves to disengage said clutch section andengage said brakc section when the work piece has completed passingbetween the second pair of facing tube ends thereby stopping third ofsaid solenoid valves to first engage said clutch 5 said sewing machine.

section thereby starting said sewing machine and then

1. In a sewing machine having a sewing head above a base arm, anattachment therefor for starting and stopping said sewing machinecomprising a clutch and brake drive unit operatively connected to saidsewing machine having an air operated brake section and an air operatedclutch section, a plurality of solenoid valves connected together withone of said solenoid valves connected to a source of air under pressure,a second of said solenoid valves connected to the brake section of saidclutch and brake unit, a third of said solenoid valves connected to saidclutch section of said clutch and brake unit, two pairs of tubes witheach pair thereof having facing, but spaced apart ends for the passageof a work piece to be sewn, said pairs of facing tube ends being spacedapart in the direction of movement of the work piece, and air operatedmicro-switches each connected to one pair of said facing tubes and toone of said first mentioned solenoid valves and electrical meansoperable by said micro-switches in sequence when the work piece passesbetween the ends of the first pair of facing tube ends for operating thethird of said solenoid valves to first engage said clutch sectionthereby starting said sewing machine and then operating the second ofsaid solenoid valves to disengage said clutch section and engage saidbrake section when the work piece has completed passing between thesecond pair of facing tube ends thereby stopping said sewing machine.